1. Field of the Invention
The present invention relates to the field of OLED (Organic Light Emitting Display) device packaging techniques, and in particular to an OLED device packaging method and an OLED packaged with the method.
2. The Related Arts
In the field of displaying technology, flat panel display devices gradually take the place of CRT (Cathode Ray Tube) display devices. Conventional flat panel display devices generally include liquid crystal displays (LCDs) and organic light emitting displays (OLEDs). Planar lighting technology is a novel light source and the development thereof has already gotten close to the stage of commercialized mass production. In the flat panel display and planar lighting technologies, bonding and welding between two flat glass panels is a technique of vital importance and the result of packaging thereof will directly affect the performance of the devices.
Ultraviolet (UV) curing is the technique that has been adopted earliest and possesses the following advantages: No solvent or a minor amount of solvent is used so that the environmental pollution caused by solvent can be reduced; energy consumption is small and curing at low temperatures is possible so as to be applicable to heat-sensitive materials; curing speed is high and efficient is also high so as to be applicable to a high speed manufacture line with the curing facility having a small floor area. However, the UV resins are organic materials and exhibit relatively large gaps between molecules after being cured so that moisture and oxygen may easily penetrate the medium to reach the interior enclosed area. Thus, they are suitable for applications where sensitivity to moisture and oxygen is not prominent, such as LCD.
Frit based packaging techniques are novel flat glass panel packaging techniques that are under development and there is generally no papers related therewith in China. It is often made by formulating glass granulates to form a solution having a predetermined viscosity for application to coat packaging glass, wherein the solvent is removed through heating for subsequent laminating with glass to be packaged. Laser is then applied to instantaneously heat and fuse the glass granulates to thereby bond the two flat panels of glass together. The frit technology is an inorganic packaging medium so that it displays excellent capability of resisting moisture and oxygen, making it particularly suitable for OLED techniques that are sensitive to moisture and oxygen.
Metal welding is a commonly used welding technique and welding technique for glass has already been long used. However, to apply metal welding between two flat panels of glass, due to the limitations that the welding temperature is not allowed to be excessively high (the temperature of a welded zone being not allowed to exceed 900° C.) and the thermal expansion coefficients of commonly used metals are different from glass (which may lead to stress), techniques of this area have not been popularized. It is thus an important issue to handle welding of glass substrate by developing a novel metal welding technique.